1. Field of the Invention
This invention relates to fluid spray nozzles such as showerheads having means for adjustably dividing fluid flowing therethrough between pulsating and nonpulsating discharge streams and, more particularly, to fluid spray nozzles utilizing axial sealing arrangement having positive shut-off characteristics.
2. Description of the Prior Art
In recent years, specialized showerheads known as "massagers" have come into widespread use. Some of these spray nozzles are capable of producing a massaging action by, periodically blocking the flow through each of a number of spray discharge openings, the result being a number of pulsating jets which in combination produce a desired massaging action. Since the user may not always desire a massaging action when taking a shower, showerheads have been provided in the past with valve means for selectively providing not only a massaging action, but also a nonpulsating spray. Similarly, showerheads have been provided in the past with various valve constructions for dividing the total flow in any desired proportion between pulsating and nonpulsating sprays. In this manner, it has been possible to obtain a wide range of shower actions ranging from a heavy massaging action (pulsating flow only) to a totally nonpulsating (continuous jets) spray. The usual practice in such spray nozzles is to provide separate groups or sets of discharge outlets for the pulsating streams and the nonpulsating streams. As a result, fluid should be discharged from only one set of discharge outlets when a pure massaging action is desired and fluid should be discharged from only the other set of discharge openings when a pure nonpulsating action is desired. When, of course, a combined action is desired, fluid will be discharged simultaneously from both sets of discharge openings.
In prior art showerheads, it has been common to provide the desired valving by means of a pair of apertured, relatively movable flat plates. More particularly, it is common to provide a first flat, stationary plate having apertures therein leading to two different groups of discharge outlets. A second flat, apertured plate is mounted over the first plate, and control means are provided externally of the showerhead housing to move the second plate between a pair of extreme end positions. In one end position, apertures in the two plates are aligned so as to direct fluid to only one set of discharge outlets. In the other end position, apertures in the two plates are aligned so as to direct fluid to only the other set of discharge outlets. In intermediate positions of the second plate, the apertures are aligned sufficiently to direct portions of the fluid to all discharge openings, the relative proportions directed to each set of discharge opening depending upon the relative positions of the first and second flat plates. In practice, it is fairly common to experience leakage between the two plates such that there is some flow to the discharge outlets intended for pulsating spray when a continuous spray only is desired, and vice versa. This leakage is most pronounced and troublesome after prolonged use of the showerhead has resulted in slight wear of the washers or seals surrounding the apertures on the flat plates. This leakage is evident to the user in the form of an undesired discharge from the nozzle in a form, most typically heavy dripping, that does nothing to contribute to either pulsating or nonpulsating shower action.